ElectroGuard Impressed Cathodic system

[Jim R]

Hi, Folks.

Has anyone tried the ElectoGuard impressed cathodic protection system (600 or 700 series)?

Electro-Guard Inc's online product catalog.

$1500 bucks or so seems like a bargain for an active system that monitors and automatically adjusts (and eliminates exterior zincs), but I'm a bit skeptical. If this works, why do all the $3-million mega-yachts in the yards have zincs all over the hull?

My boat is a 50-foot wooden trawler, by the way.

Thanks!

 

[Fletcher500]

I know enough about this topic to be dangerous, but did some research awhile back when I was chasing potential galvanic issues, that turned out to be something else. What I also found is there are not many people who truly understand this field, even the "experts". I don't know anything about the product, but I would be very skeptical.

 

[Gulf Comanche]

I’ve had them on Old School for 10 years now. The boat is all aluminum and lives in fresh water 90% of the time. So far, so good. No idea how they work. If she lived in salt water it might be a different story, but have no idea.

 

[ancora]

Our boat came with the system and it has worked fine for the 18 years we've owned it. Just two plate zincs on the transom is all that is needed to protect the boat.

 

[Lou_tribal]

Our boat came with the system and it has worked fine for the 18 years we've owned it. Just two plate zincs on the transom is all that is needed to protect the boat.

Isn't two plate zinc the common setup on most of boats even without this system? (Plus shaft one and rudder one).

L

 

[tiltrider1]

Yes the system works.

You have a reference anode, needs to be replaced every 3 years. Then you have an anode that provides power for the system, needs replacing every 3 years as well. Then you need a standard diver’s dream zinc this is your sacrificial anode. The system allows just enough current to flow to reduce the potential of all bonded metals .5 volts.

Because of the reduced current flow the diver’s dream will usually go a year before it needs replacing. The system comes with shaft wipers so you can monitor each shaft being sure that continuity hasn’t been lost. The reason we put zinc on shafts and rudders is not the need for more zinc but to protect them from continuity loss.

Is it worth it? The answer is maybe. For 15 years I put a dry suit on once a year, jumped in the water and change out the divers dream with only a snorkel. Normally zinc’s are done 3 times a year for an annual cost of $600. So it depends on what your diver costs are.

 

[Xsbank]

Sorry, need more info but it sounds like snake oil. (Running and ducking for cover).

 

[Jay N]

Purchased and installed one of these systems on my last boat, a 40' all wood Ed Monk bridge deck sedan which we owned from 1974 to 1997. During the early years, it was apparent that the wood experienced over protection when the zinc anodes were new, then a period of good protection, then if it went too long, under protection.

What the Electroguard impressed cathodic protection system did for this boat was to smooth out the protection, so that wood electrolysis does not occur when the anodes are new, and under protection was minimized. Over protection can be more of a problem for wood boats then under protection.

Good system, don't need it on our fiberglass boat.

 

[gaston]

When someone says it works what are they comparing it to one that dosn't ??

 

[boomerang]

Yes the system works.

You have a reference anode, needs to be replaced every 3 years. Then you have an anode that provides power for the system, needs replacing every 3 years as well. Then you need a standard diver’s dream zinc this is your sacrificial anode. The system allows just enough current to flow to reduce the potential of all bonded metals .5 volts.

Because of the reduced current flow the diver’s dream will usually go a year before it needs replacing. The system comes with shaft wipers so you can monitor each shaft being sure that continuity hasn’t been lost. The reason we put zinc on shafts and rudders is not the need for more zinc but to protect them from continuity loss.

Is it worth it? The answer is maybe. For 15 years I put a dry suit on once a year, jumped in the water and change out the divers dream with only a snorkel. Normally zinc’s are done 3 times a year for an annual cost of $600. So it depends on what your diver costs are.

I'm not understanding your point here so educate me. The reason I've always put zincs on my shafts & rudders is to add a less noble material to the underwater hardware & let it be the sacrificial metal rather than the bronze hardware. What do you mean "to be sure continuity isn't lost"? Do you mean continuity through the water? That's what the bonding does.
If I had to change my zincs 3 times a year I wouldn't say that is normal! I'd be freaking out! I always get a season out of a shaft zinc & a rudder zinc. They're about spent after one season but that way I know they're working. If they're severely eaten up, I go looking for a problem.

 

[boatpoker]

Impressed current systems have been around for decades and proven to work when set up and maintained properly. ABYC even has a standard for them and most Mercury Marine engines have come with them as standard equipment (Mercathode brand) for many years.

 

[tiltrider1]

When someone says it works what are they comparing it to one that dosn't ??

If you install an electro guard your boat will be protected and you will consume less zinc. You will also know when your zincs are under performing. I can not tell you if this is worth the cost to you. If you have a wood boat there is a very definite cost value.

 

[Fletcher500]

If this system has been proven to be more effective than spot zincs, than I would assume larger steel vessels in the fishing and work boat class use them also?

 

[ancora]

We have owned Ancora for 18 years and have never replaced the reference zinc. As long as we can keep the meter in the "green" I figure the system is working.

 

[MurrayM]

1) Would a prop shaft zinc still be needed?

2) What justifies the additional $1,200.00 cost above a galvanic isolator?

 

[Jim R]

1) Would a prop shaft zinc still be needed?

2) What justifies the additional $1,200.00 cost above a galvanic isolator?

Well, the isolator protects from stray AC while you are plugged in. I would say that the added protection the ElectroGuard system (theoretically) brings is regulation of galvanic protection when you are unplugged.

 

[MurrayM]

Well, the isolator protects from stray AC while you are plugged in. I would say that the added protection the ElectroGuard system (theoretically) brings is regulation of galvanic protection when you are unplugged.

Would help if I knew the difference between electrolysis and galvanic corrosion, eh?

Electrolysis occurs when an electrical current strays from its path due to improper wiring or a defect coming between two metals in the presence of an electrolyte, usually seawater in this case. Metal hull boats are particularly at risk because the hull is conductive and stray wire or connections use the hull as a ground. The two metals can be the same or different.

Galvanic corrosion is when two different metals are in contact in the presence of an electrolyte. One metal will be more chemically active than the other, and a reaction occurs. Very pure water will not conduct electricity, so the electrolyte isn’t present. Saltwater however conducts an electrical current and allows for corrosion to occur.

 

[Nightsky]

Sorry, need more info but it sounds like snake oil. (Running and ducking for cover).

I tend to agree. I had one installed on a new build salmon troller in the 80s. The sales pitch was that different species of salmon and tuna are are more attracted to a boats hull potential if it falls within a tight range, which these devices could dial in. Unfortunately, when salmon and tuna decide to bite is so capricious, that one could never be sure if the bite was caused by the device or if the fish just decided it was time. IMHO, save your money. Make sure all under water metals are properly bonded to a good sacrificial anode. I agree that it is possible to over protect a wood boat. You can install a relatively inexpensive hull monitor that will tell you the state of the anodes if you are really concerned. A good marine electrician should be able to tell how much protective anode you need depending on hull material.

 

[foggysail]

Our boat came with the system and it has worked fine for the 18 years we've owned it. Just two plate zincs on the transom is all that is needed to protect the boat.

OK...I know zilch about the system other than how it should work. But the reason for my post is that I have shaft brushes that tie into the my boat’s bonding system and use only one (1) transom anode. It is aluminum, sized 6X12X1” and this takes care of my galvanic corrosion issues as I verify various times during the season using my half bridge.

So you have a galvanic protection system that you say has worked fine over the last 18 years but you also go on to say that you have two zinc plates on the transom. So I am a little confused. Do the zincs ever wear out by providing protection OR are they providing the means for adding current to the bonding system? No, I am not picking on your system at all. Just trying to understand it because with such a system you should not need any sacrificial anodes.

 

[foggysail]

Impressed current systems have been around for decades and proven to work when set up and maintained properly. ABYC even has a standard for them and most Mercury Marine engines have come with them as standard equipment (Mercathode brand) for many years.

YES! and they are found in many places such as bulkhead, bridges and other places where galvanic corrosion can occur. With these systems there should be no need for sacrificial anodes.

 

[tiltrider1]

I'm not understanding your point here so educate me. The reason I've always put zincs on my shafts & rudders is to add a less noble material to the underwater hardware & let it be the sacrificial metal rather than the bronze hardware. What do you mean "to be sure continuity isn't lost"? Do you mean continuity through the water? That's what the bonding does.
If I had to change my zincs 3 times a year I wouldn't say that is normal! I'd be freaking out! I always get a season out of a shaft zinc & a rudder zinc. They're about spent after one season but that way I know they're working. If they're severely eaten up, I go looking for a problem.

In the modern era all under water metal on a boat is connected together using a bonding wire. If you connect zinc to this bonding system it becomes the most noble there by sacrificing itself to protect he rest of the boat. It does not matter if this zinc is on the rudder, shaft or a bonded stud on the transom as long as ther is electrical continuity between all. But how do you know if there is electrical continuity between your shafts and the bonding system? You don’t but if you hang zinc on your shaft you know your shaft is safe. How do you know when it’s time to change your zincs. You don’t, that’s why some people change them 3 times a year and others only when the zinc is gone. Just because there is zinc left does not mean there is enough zinc to give full protection. Electro guard tells you if your shafts have electrical continuity and if your zincs are up to the job or need changing. With electroguard you only use a zinc plate attached to the boats transom.

Is it worth the money? Well that’s up to the individual.